#include <iostream>
using namespace std;

int sum(int a, int b=20)
{
	int result;

	result = a + b;

	return (result);
}

int main ()
{
	// 局部变量声明
	int a = 100;
	int b = 200;
	int result;

	// 调用函数来添加值
	result = sum(a, b);
	cout << "Total value is :" << result << endl;

	// 再次调用函数
	result = sum(a);
	cout << "Total value is :" <<
	result << endl;

	return 0;
}

